The present invention relates to an improvement in a post-printing processor for a printer.
In a recent business office environment, each person is usually provided with a personal computer that is connected to a plurality of other computers via a network.
One or more printers for printing out the works processed by the personal computers are also incorporated in the network to selectively be used by a plurality of shared users. However, printed jobs from the plurality of shared users are often stacked up together at a discharging port of the printer. Thus, after a printing operation, the user has to walk up to the printer and look for his/her job in a stack of jobs of other users.
Thus, printers used by a plurality of shared users require a post-printing processing for separating the jobs for users to help each user to easily pick up his/her job. This post-printing processing is more strongly demanded as the number of shared users connected to the network becomes larger.
As such a post-printing processing technique, a sorter is known in which a plurality of sheet-discharging ports are assigned to respective users and can automatically be selected by a controller of the printer to prevent jobs of different users from commingling. However, post-printing processing by this type of sorter requires multiple sheet travel paths and a mechanism for switching among the sheet travel paths for guiding jobs to the plurality of discharging ports, which results in a large-scaled device structure. Accordingly, such sorter has problems of a high installation cost as well as an unreasonably limited number of users despite of the expense, and thus is rarely employed.
In view of these problems, the following processes which employ simple mechanisms are known as processes that can be employed at a low cost by multiple users. Hereinafter, conventional post-printing processes that are used in practice will be described together with their problems.
FIG. 11 is a view showing the most major post-printing processor that is used in practice, where a job 200 currently under the process is discharged through a discharging roller 101 in a longitudinal direction and stacked up on already discharged jobs of other users.
The jobs of other users beneath the currently processed job 200 are stacked up in alternating directions such that the first job 201 is in the longitudinal direction, the second job 202 is in the transverse direction, the third job 203 is in the longitudinal direction again and the forth job 204 is in the transverse direction again. This type of sorting is accomplished by providing two sheet cassettes (not shown) for stocking sheets in the longitudinal and transverse directions. A controller of the printer alternately switches between the longitudinal and transverse directions for each job sent from the users via the network.
FIG. 12 is a view showing another exemplary simple sorting mechanism which can be mounted on a printer 100. The small-sized sorter 103 which may be mounted as an option on a sheet discharger 102 of the printer 100 is configured to output jobs while the printer 100 switches between a sheet-conveying path directing to a standard discharging port 104 and a sheet-conveying path directing to the sorter 103. The sorter 103 is provided with a plurality of sheet-discharging ports A, B, . . . N, and an internal conveying path switching mechanism for separating sheets by job. An internal controller of the sorter 103 may look for an empty discharging port to discharge a single job, or the sheet-discharging ports may be assigned to respective users in advance to serve as user-specific discharging ports.
The first conventional method shown in FIG. 11 which alternately switches the sheet discharging directions requires two sheet cassettes for both longitudinal and transverse discharges. A sheet cassette requires a number of machinery components and a large-sized body, for example, for identifying a type of a stack of sheets set in the cassette, for picking a single sheet from the stack of sheets, and for forming a conveying path for the stacked sheets. Accordingly, the sheet cassette is expensive as an option and will increase an installation cost. In addition, when either of the two cassettes is low of paper stock, the printer detects xe2x80x9cpaper lowxe2x80x9d signal, which means that the maximum number of sheets that can actually be printed is not so large in spite of the size of the device.
Although each job may be stacked up in alternating directions, the jobs are not always removed in this order. For example, a job in the transverse direction may be picked up first, leaving the adjacent jobs in the longitudinal direction commingled.
The greatest problem here is that the user has to look through the stacked jobs at the printer to find his/her job.
A printer mounted with the sorter shown in FIG. 12 requires a certain strength to bear the weight of the mounted sorter 103 as well as the total weight of the discharged sheets on a small area of the top of the sheet discharger 102. Thus, the printer 100 would cost high to ensure this strength as well as to provide the switching mechanism for conveying sheets in vertical and horizontal directions.
The mechanism for switching among the sheet-discharging ports A through N complicates the configuration of the discharger, increases the cost of the controller and requires a large power source, resulting in an increase of the cost of the sorter 103 itself. Moreover, since the number of the discharging ports is limited due to the mounting-type structure, the discharging ports are likely to become full unless the users come quickly enough to remove their jobs.
Thus, post-printing processor has been considered to have no merit or achievement of being developed at a great cost as an optional device, since this would further raise the price. As a result, despite of their convenience, the above-described post-printing processors have never been popular.
In sum, the conventional post-printing processors are associated with the following problems. First problem is that both of the alternative-direction stacking technique and the simple sorter configuration technique increase the installation cost borne by the user due to the indispensable device structure.
Second problem is that in the case of the alternative-direction stacking technique, the user has to actually look through the jobs discharged from the printer to find his/her job. In the case of the simple sorter configuration technique, the limited number of discharging ports become full in short time, which will interfere with the sorting function.
Thus, the present invention has an objective of providing a post-printing processor which solves the above-described conventional problems, and reduces the installation cost borne by the user and facilitates locating of the desired printed job.
The present invention is a post-printing processor for a printer, which can process a plurality of print jobs. In view of the above-described problems, the post-printing processor specifically comprises: spiral shape sheet-holding members rotatably arranged to face a sheet-discharging port of the printer such that the center axes of the spiral shape sheet-holding members are generally perpendicular to a sheet conveying plane of the sheet-discharging port; and a rotating mechanism for retaining the rotating positions of the spiral shape sheet-holding members such that openings of the gaps of the spiral shape sheet-holding members face the sheet-discharging port, and for driving the spiral shape sheet-holding members to make one or more full-turns after every single print job is completed.
According to this structure, a sheet sent out from the sheet-discharging port of the printer is inserted into the spiral shape sheet-holding members which are arranged to face the sheet-discharging port. Since the positions of the spiral shape sheet-holding members are retained such that the openings of their gaps face the sheet-discharging port, the spiral shape sheet-holding members do not interfere with the insertion of the sheet. Accordingly, sheets of a single print job are continuously discharged from the sheet-discharging port of the printer, and inserted into and stacked on the gap of the spiral shape sheet-holding members. When the printing operation of the single print job is completed, the rotating mechanism is actuated to drive the spiral shape sheet-holding members to make one or more full-turns. The spiral shape sheet-holding members are driven to make full-turns so that the openings of their gaps return to the positions where they face the sheet-discharging port. For example, the full-turns may be a single full-turn. After the full-turn, the sheets of the single job are elevated for a pitch of the spiral in the axial direction of the spiral shape sheet-holding members. By repeating this operation after every single print job is completed where every print job is sent a pitch downstream in the axial direction of the spiral shape sheet-holding members, the print jobs can be held separate from each other in the gaps of the spiral shape sheet-holding members at respective pitch levels.
Since the print jobs are separated at respective pitch levels, users can easily find and collect his/her print job. There is no need of providing multiple sheet cassettes for switching between the directions of the discharged sheets, and thus the structure of the printer can be simplified. The spiral shape sheet-holding members have simple spiral structure, and thus the post-printing processor can be produced at low cost. The contents of the print jobs in the spiral shape sheet-holding members can easily be confirmed. Even when a print job is removed away from the spiral shape sheet-holding members, the remaining print jobs do not commingle with each other and remain separate from each other.
The jobs left by the users are sent to the downstream end of the spiral shape sheet-holding members, where they are collectively accumulated. This allows successive printing operation until the entire sheet stock is used up. The number of print jobs that can be held separate by the spiral shape sheet-holding members is limited by the number of pitches of the spiral shape sheet-holding members. For example, when the number of the pitches is N and the spiral shape sheet-holding members are driven by the rotating mechanism to make a single full-turn per print job, print jobs for the last N number of operations can distinctly be held separate. Unlike a sorter which can only distribute print jobs into a limited number of sheet-discharging ports, the print jobs processed by the invention can continuously sent downstream of the processor. Thus, the print jobs left by the users do not interfere with operations of new print jobs.
The spiral shape sheet-holding members may be arranged in parallel at the both sides of the sheet-discharging port, and the rotating mechanism may be configured so as to synchronously rotate the spiral shape sheet-holding members.
According to this structure, the sheets sent out from the sheet-discharging port of the printer can be held by two spiral shape sheet-holding members arranged at the sides of the sheet-discharging port, thereby enhancing stability of holding sheets.
When the spiral shape sheet-holding members are arranged in parallel at the both sides of the sheet-discharging port, the spiral shape sheet-holding members are preferably wound in symmetrical directions, and the rotating mechanism is preferably configured so as to synchronously rotate the spiral shape sheet-holding members in symmetrical directions.
By doing so, friction against the sheet sent out from the sheet-discharging port can be compensated in right and left directions, thereby preventing sliding of the discharged sheet in the transverse direction. Another pair of spiral shape sheet-holding members in parallel can also be provided next to the first pair of spiral shape sheet-holding members in the sheet traveling direction. For example, two pairs of spiral shape sheet-holding members can be provided to hold the four corners of sheets sent out from the sheet-discharging port.
Furthermore, for a printer connected to a network, the post-printing processor may further comprise: an identifying information generating member for generating identifying information unique to a print job received by the printer; an identifying information transferring member for transferring the identifying information to a terminal device that has commanded processing of the print job via the network; and a print job holding result displaying member for displaying the relationship between the identifying information for the print job and the gap of the spiral shape sheet-holding members.
By doing so, whenever the printer receives an order of a printing operation, unique identifying information is generated by the identifying information generating member, and sent to the terminal device that has ordered the printing command via the identifying information transferring member and the network. The print job holding result displaying member displays the relationship between the identifying information and the gap of the spiral shape sheet-holding members, that is, the relationship between the identifying information and the held position of the print job corresponding to the identifying information.
Thus, the user can confirm the identifying information for the print job on his/her terminal device, walk up to the printer, and refer to the print job holding result displaying member of the post-printing processor to locate the gap of the spiral shape sheet-holding members holding his/her print job, thereby easily collecting his/her print job.
The print job holding result displaying member may comprise a plurality of display elements arranged in the axial direction of the spiral shape sheet-holding members at intervals of pitches corresponding to the number of full-turns made by the spiral shape sheet-holding members after every completion of a single print job.
For example, when the number of full-turn made after completion of a single print job is one, the display elements are provided at pitch intervals in the axial direction of the spiral shape sheet-holding members. Each of the display element displays the identifying information for the print job held in the corresponding gap.
Thus, the user can refer to the identifying information for the print job on his/her terminal device, and collect his/her print job from the gap corresponding to the display element with that identifying information.
The print job location displaying member may comprise a plurality of identifiable markings arranged in the axial direction of the spiral shape sheet-holding members at intervals of pitches corresponding to the number of full-turns made by the spiral shape sheet-holding members after every completion of a single print job, and identifying information displaying members for displaying the identifying information of the print jobs in correspondence with the respective markings.
According to this structure, fixed markings are provided in the axial direction of the spiral shape sheet-holding members. Based on the markings and the identifying information displayed on the identifying information displaying member, the user can find his/her print job. Specifically, the user can collect his/her print job from the gap provided with the marking corresponding to the identifying information displayed on his/her terminal device. The fixed markings can simply be printed or carved on the body of the post-printing processor. The identifying information displaying member may utilize a liquid crystal display or the like of the printer, which is advantageous in reducing the production cost of the post-printing processor.
Instead of the identifying information, the identifying information displaying member may display the user""s name of the terminal device that has ordered the printing operation.
In this case, it is not necessary to transfer the identifying information to the user""s terminal device, and thus the identifying information generating member and the identifying information transferring member are not necessary. The user can locate his/her print job in the spiral shape sheet-holding members based on the markings and his/her user""s name displayed on the identifying information displaying member. Since this does not require communication of the identifying information via the network, the network traffic jam can be eased.
The post-printing processor may comprise: a plurality of regulating pieces for regulating the fore-end of a sheet sent to the spiral shape sheet-holding members; a regulating piece positioning member for adjusting the positions of the regulating pieces according to the size of the sheet; and a regulating piece driving member for moving each of the regulating pieces in the axial direction of the spiral shape sheet-holding members synchronously with the sheet conveying rate associated with the rotation of the spiral shape sheet-holding members.
According to this structure, the back-ends of the print job sent to the spiral shape sheet-holding members are uniformly aligned regardless of the sizes of the sheets. As a result, even when sheets of different sizes are used for respective print jobs, the print jobs can readily be removed.
The gaps of the spiral shape sheet-holding members are not necessarily equal. For example, the gap immediately adjacent to the sheet-discharging port may be formed to be relatively large.
By making the gap immediately adjacent to the sheet-discharging port (the gap for initially receiving the print job from the printer) larger, the sheets are prevented from being stuck and can smoothly be sent from the printer to the spiral shape sheet-holding members. Since discharged print jobs are held sufficiently far from the discharging port, undesirable interference of the print job with the printer upon removing the print job can be avoided and thus the newest print job can easily be removed. The gaps of the spiral shape sheet-holding members and the regulating pieces travel in a synchronous manner by the regulating piece driving member. Even when a certain pitch is different from others, the positional relationship between the gaps and the regulating pieces may be maintained by making the widths of the regulating pieces large.